Routing Error No route matches [GET] "/users/logout"

The message "Routing Error No route matches [GET] "/users/logout" is because you are sending the request via get and should be delete, so to fix it you have two options:

 The first one  is the  better, change the tag  link_to to button_to, doing that, rails will  do  the dirty work to send it as  a delete request.

The second one is not recommended, since DELETE is the appropiete RESTFUL query , but it works. Got to devise.rb change  config.sign_out_via = :delete to config.sign_out_via = :get